, llroundl

Synopsis

Description

These functions rounds their argument to the nearest integer value, rounding halfway
cases away from 0 regardless of the current rounding direction.

Return Values

Upon successful completion, these functions return the rounded integer value.

If x is NaN, a domain error occurs and an unspecified value
is returned.

If x is +Inf, a domain error occurs and an unspecified value
is returned.

If x is -Inf, a domain error occurs and an unspecified value
is returned.

If the correct value is positive and too large to represent as
a long long, a domain error occurs and an unspecified value is returned.

If the correct value is negative and too large to represent
as a long long, a domain error occurs and an unspecified value is
returned.

Errors

These functions will fail if:

Domain Error

The x argument is NaN or ±Inf, or the correct value is not representable as an integer.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception will be raised.

Usage

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling
these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is
non-zero, an exception has been raised. An application should either examine the
return value or check the floating point exception flags to detect exceptions.

These functions differ from the llrint(3M) functions in that the default rounding
direction for the llround() functions round halfway cases away from 0 and
need not raise the inexact floating-point exception for non-integer arguments that round to
within the range of the return type.